Breeding practices over the years have inadvertently promoted and sustained a rather large number of genetic diseases, e.g., cancer and urinary system disorders, in cats and other animals (Vella et al., 1999). For example, several million domestic cats in the U.S. are predisposed to developing urinary system disorders, e.g., congenital urinary tract defects, polycystic kidney disease, neoplasia, renal failure, interstitial cystitis, urocystolithiasis, obstructions in the urethra or other parts of the urinary system, and urinary incontinence (Lekcharoensuk et al, 2001). Moreover, the ubiquitous mixed breed cat known as the domestic short hair and especially one of its parent breeds, the Siamese, have high cancer incidence rates with multiple malignancies occurring in relatively young cats (Vella et al., 1993; Hayes et al., 1981). The tumors seen in these breeds of cats are often sarcomas of soft tissues and bone. Before spaying of female kittens became a common practice, mammary tumors were the most common type of malignancy in cats (Ogilve and Moore, 1995).
Over the past decade, the incidence of sarcomas in cats has risen sharply with the mandatory administration of vaccines that commonly produce pronounced inflammatory reactions (Hendrick and Goldschmidt, 1991; Hendrick et al., 1992; Kass et al., 1993; Doddy et al., 1996; Banerji et al., 2001; Macy and Hendrick, 1996). While malignant transformation at injection sites has been documented in humans and other species, vaccine associated feline sarcoma (VAFS) has emerged as a serious problem in feline medicine with as many as ten-thirteen of every 10,000 vaccine injections leading to tumor formation (Macy and Hendrick, 1996; Marmelzat, 1968; Archampong and Clark, 1970). Since more than 53 million pet cats are administered one or more vaccines each year, a sizeable number of cats are at risk of developing the disease.
Diagnosing diseases in animals is not always an easy task. There are many examples of cases where the pets are treated repeatedly without resolution of the symptoms. In such cases, knowledge of a genetic predisposition to disease, e.g., cancer, VAFS, or a disorder of various organs such as the urinary system, endocrine system or cardiac disorder would indicate the possibility of disease development in the animal. Knowledge of disease predisposition in an animal would be extremely important in making treatment and management decisions. For example, certain treatment options may be less beneficial or even harmful to an animal predisposed to developing a disease such as cancer, VAFS, or a disorder of the urinary system. Regarding cancer, the availability and use of radiation therapy for treatment of cancers is increasing. This otherwise beneficial treatment may induce additional tumors in cancer-predisposed individuals. As for VAFS, cats that are predisposed to developing sarcomas at vaccination sites may benefit from special care and vaccination protocols during their lifetimes. Exposure to known physical, chemical or biological carcinogens could be eliminated or reduced and the individuals could be maintained on controlled diets. Routine visits to the veterinarian would include special attention to visible or palpable masses and other symptoms of possible disease development. Moreover, animals that are found to be predisposed to developing diseases or disorders of the urinary, cardiac, or endocrine systems are also likely to benefit from special care, diet, and medication during their lifetimes. In addition to preventive health maintenance, a simple genetic test would enable breeders to identify carriers and avoid mating animals that are susceptible to developing disease. Analysis of the incidence of a biomarker, e.g., a predisposing allele, in registered cats of various breeds would allow breeders to choose amongst cats without the disease-associated marker for perpetuating and improving the health of these breeds.
Thus, what is needed is a test for a molecular biomarker(s) that would allow pet owners and veterinarians to make informed decisions. What is needed is a test for detecting the predisposition of an individual to a disease such as cancer, e.g., VAFS, and/or the predisposition to a non-cancerous pathology including a disorder of the urinary, cardiac, and/or endocrine system. What is also needed is a diagnostic kit for such a test.